Paper-pulp screen.



.- No. 721,875. PATENTED MAR. 3,1903.

W. R. & H. R. PARNSWORTH.

PAPER. PULP SCREEN. APPLICATION FILED MAR. 10, 1902.

N0 MODEL.

TIIEI'IIIIII I I l r |||||l| :51:" lrgg s UNITED STATES PATENT OFFICE.

WVILLIAM R. FARNSVVORTI-I AND HILAND R; FARNSI/VORTH, OF TURNERS FALLS, MASSACHUSETTS.

PAPER-PULP SCREEN.

SPECIFICATION forming part of Letters Patent No. 721,875, dated March 3, 1903. Application filed March 10, 1902. Serial No. 97,501. (No model.)

To all whom, it may concern:

Be it known that we, WILLIAM R. FARNS- WORTH and HILAND R. FARNSWORTH, citi- Zens of the United States of America, residing at Turners Falls, in the county of Franklin and State of Massachusetts, have invented new and useful Improvements in Paper-Pulp Screens, of which the following is a specification.

This invention relates to the construction of screen-boxes for paper-pulp; and the invention has for its object the provision of means for removably securing screen-plates in the screen-boxes, to the endthat they may be easily removed for cleaning purposes and at the same time so secured in operative position that no pulp can be washed through the screen under the edges of said plates; and

' the invention consists in the construction hereinafter set forth in the following specification and clearly pointed out in the claims.

In the drawings forming part of this application, Figure 1. is a plan View of a portion of a screen, partly broken away, and showing two screen-plates secured thereto, two of the plates being removed. Fig. 2 is a longitudinal sectional elevation of Fig. l on line 2 2, and Fig. 3 is a transverse sectional View on line 3 3, Fig. 1. Fig. 4 is a perspective view of a part of one of the locking devices for the longitudinal edges of the plates.

The drawings forming part of this application show a screen-box, such as is usually employed on a Fourdrinier paper-machine, and though this is its principal use it may be otherwise applied, if desired.

In carrying our invention into practice in its application to paper-making machines the usual rectangular box-like frame a is provided, open at the top and bottom, of course, the screen-plates b, suitably supported therein, constitutinga horizontal partition for said frame. Near the bottom of the latter and extending entirely around its interior is an inwardly-projecting ledge formed by the strip 0, on which each end of the screen-plates b is supported and likewise one edge of one plate at each end of the frame. These screenplates are made of relatively narrow widths and are of brass, as usual, and the longitudinal edges thereof are beveled, said bevel being outwardly inclined from the upper edge of said plates. The dimensions of these plates lengthwise adapt them to fit closely between the opposite sides of the box or frame a, and

the beveled edge of the first plate and of the last plate fit under similarly-beveled edges of a metal strip d, secured across each end of the box on the top of the strips 0. Parallel with the ends of the frame a, to which these strips (1 are attached, there are located the supporting bars 6, and midway between these bars or between one of said bars and the inner wall of the frame a are located the parallel separated bars f. On top of the supporting-bars e is a plate g, having in its opposite edges beveled grooves for receiving the edges of the screen-plates b. It is ap parent, therefore, that the ends of the frame a and the plates 9 on the supporting-bars e constitute abutments against which the longitudinal edges of the plates may be forced .to make a tight joint, and the means whereby these screen-plates are forced apart in opposite directions to attain this end consists in a beveled locking-plate h. (Shown in perspective view in Fig. 4;.) This plate, as

shown, consists of a vertical web which fits in between the parallel bars f, whose upper edge is widened out and suitably beveled to correspond with the beveled edges of the screen-plates b, contiguous to it. On the web of this plate it there are lugs 1', (shown clearly -in Figs. 3 and 4,) which project in the general direction of said plate beneath pins 3', which extend transversely through the bars f. These plates 71, and their lugst' are so located relative to the pins 3' that when said plates are moved in one direction they will by that act have their beveled upper portions drawn down against the beveled edges of the plates between which they are located by the contact of the beveled edge of the lugs i with the pinsj. Any suitable means may be employed for effecting this endwise movement of the locking-plates h; but a desirable way of imparting movement thereto is shown in the drawings, and it consists in fixing a bush ing in the frame a, as shown in Figs. 1 and 3, so located that a screw m, working therein, may be screwed inwardly against the end of said plate to move it in one direction or to draw it in the opposite direction by a re verse movement of said screw. Preferably the screw is provided with a check -nut n to lock it.

Obviously in order to provide the proper endwise movement to the locking-plates h they must be shorter than the screen-plates b, and consequently there will be an open space (indicated by 0, Fig. 3) between the end of said plate and the side of the frame; but this space is entirely covered by the means provided for stopping off the ends of the screen-plates b, so that there may be no leak between said ends and the sides of the frame contiguous thereto. These means consist in providing a strip, preferably of wood, (indicated by 13,) extending from one side of the frame a to the other, across the ends of all the screen-plates and across the ends of the locking-plates h. This strip 19 has its upper edge beveled, as shown in Fig. 3, which beveled edge is adapted to be drawn under the edge of an oppositely-beveled strip q, secured to the sides of the frame a. These strips 19 may be drawn up into position in any suitable manner, preferably by means of a screw-threaded bolt r, one end of which is fixed in said strip 19 and the other end of which is engaged by a suitable nut s on the outside of the box. The proportions of the strip p are such that when it is screwed up sufiiciently to clamp the ends of the screenplates 1) tightly against the strips 0 it will come to a bearing against the side of the frame a, all as shown in Fig. 3.

From the above description it is clear that the screen-plates to the extent of any desired number may by the herein-described means be secured in a suitable screen-box in such manner as to provide an absolutely plane surface over the entire extent thereof, the top of the plates h and 9 being so proportioned that when the screen-plates b are locked in position the upper surface thereof will be flush with the upper surfaces of said plates h and g.

To remove any one of the screen-plates b for the purpose of cleaning it, the strips]? are first loosened, one of them preferably being removed. The screw m is then operated to loosen the locking-plate h by drawing it out of engagement with the pinsj, and either of the screen-plates which is held in place by this plate It may then be lifted out, cleaned, and put back without disturbing the others, or, if desired, all the screen-plates may be removed at the same time.

While it is desirable in some cases that the plate g and the locking-plate h be alternately applied as above described, it is not essential that this construction should always be followed, for the undercut metal strips d at each end of the box may serve as the abutments for the screen-plates b, the locking-plates it in such cases being located between the contiguous edges of adjacent plates, and the said plates, the latter being provided with oppositely-beveled edges located over said supports, and a beveled locking-bar between said edges, combined with meanslocated beneath the plane of the screen-plates, and operable through the side of the frame to force the looking bars down between the edges of said screen-plates to secure the latter to said supports.

2. A pulp-screen consisting of a suitable frame, screen-plates constituting a transverse partition therein, means of support for opposite borders of said plates, a beveled clamping-strip, and a beveled abutment for said strip located above said screen-plate supports, and means for forcing said strip under said abutment to effect the clamping of the borders of said plates to their support.

3. A pulp-screen consisting of a suitable frame, screenplates constituting a transverse partition therein, means of support for opposite borders of said plates, a beveled clamping-strip, and a beveled abutment for said striplocated above said screen-plate supports, and means operable from the outside of the screen-frame for forcing said strip under said abutment, to eifect the clamping of the borders of said plates to their support.

4. A paper-pulp screen comprising a frame, screen-plates constituting a transverse partition in said frame, supports for the screenplates, the latter being provided with beveled edges located over said supports, a beveled locking-bar between said edges,means located below the plane of the screen-plates, and 0perable from a point outside of the frame, for drawing said bar between the edges of said plates, and a strip adapted to be forced down over the ends of said screen-plates, whereby by means of said strips and said locking-bar the edges of said plates may be sealed.

5. A pulp-screen consisting of a suitable frame, screen-plates constituting a transverse partition in said frame, supports for said plates, the latter being provided with oppositely-beveled edges located over said supports, an abutment for the plates located on two opposite sides of the frame, and having an undercut edge for receiving the edge of the plate adjacent thereto, locking-bars located between the contiguous edges of said plates and having beveled portions thereon for engaging the edges of the plates, and means located beneath the plane of the said plates and operable through the side of the fra me to force the locking-bars down between the edges of the screen-plates to force the latter toward said abutments.

6. A paper-pulp screen consisting of a suitable frame, screen-plates constituting a transverse partition in said frame, supports for said'plates, the latter being provided with oppositely-beveled edges located over said supports, and a beveled locking-bar between said edges, combined with means for moving said lockin g bars in a downwardly-inclinin g direction into contact with the contiguous edges of said plates, to secure the latter to said supports.

7. A paper-pulp screen consisting of a suitable frame, screen-plates constituting a transverse partition in said frame, supports for said plates, the latter being provided with oppositely-beveled edges located over said supports, and a beveled locking-bar between said edges, a wedge-formed lug on the locking-bar, an abutment for the lug, and means for moving the bar endwise whereby the movement of the lug against its abutment may draw said bar against the beveled edges of said plates to secure the latter to their supports.

8. A paper-pulp screen consisting of a suitable frame, screen-plates constitutinga transverse partition in said frame, supports for said plates, the latter being provided with oppositely-beveled edges located over said supports, and a beveled locking-bar between said edges; a screw operable from outside the frame bearing against the end of the lockingbar, a wedge-formed lug on the latter, and an abutment for the lug on the support; said bar being endwise movable by means of said screw to carry the lug against its abutment.

W'ILLIAM R. FARNSWORTH. HILAND R. FARNSWQRTH.

Witnesses:

O. W. HOSMER, G. H. SHATTUOK. 

